A device of this type is known from French patent FR 2 658 739.
The fluid contained inside the bag can be expelled by means of a pump that operates without intake of air, or under pressure from a propellant gas present outside the bag but inside the receptacle.
As the bag empties, it shrinks and forms folds.
In some cases, it has been found that the folds or deformations can lead to the bag being torn or pierced, thus making the device unusable.